摘要
山地掉层结构考虑坡地开挖工程量、边坡稳定性等因素,常需设置多个接地端,导致结构平面和立面不规则,扭转效应显著。为研究3个不等高接地端的多台地掉层钢筋混凝土(reinforced concrete,RC)框架结构的扭转效应及控制措施,通过拟静力试验和振动台试验结果验证了有限元模型的可靠性,对建立的16个不同结构参数的有限元算例模型进行了弹性和弹塑性动力有限元分析,研究了此类框架结构扭转效应受接地端跨数、总掉层数、中接地端掉层数等因素的影响程度;通过算例分析对比了不同扭转控制措施的效果。研究结果表明:弹性状态下,3台地掉层RC框架结构在中接地层和上接地层处扭转效应显著,总体扭转效应小于对应的2台地掉层RC框架结构;而当结构进入弹塑性状态后,通过降低结构掉层部分长度在顺坡向总长度上的占比,可有效缓解结构的扭转效应;在3台地掉层RC框架结构中设置水平接地构件、钢支撑和黏滞阻尼器均能改善扭转效应,对于岩质边坡,设置水平接地构件对各扭转效应指标的改善最好。
Considering factors such as slope excavation quantity and slope stability,RC frame structures supported by foundations with different elevations(FSSFDEs)often occur,resulting in irregular structures and significant torsion.To study the torsional effects and corresponding control measures for FSSFDEs,the reliability of the finite element model was verified using pseudo-static tests and shaking table tests.Sixteen finite element models with varying structural parameters were analyzed using both elastic and elastoplastic dynamic finite element analysis.The study examined the influence of factors such as the total number of dropped stories,the number of spans and the number of dropped stories at the intermediate ground embedding end,and the number of spans at the upper ground end on the torsional effects of the structures.Additionally,the effectiveness of different torsional control measures was compared through case analysis.The main conclusions are as follows:In the elastic state,the torsional effect of RC frame structures with three different ground elevations is significant in the stories at the intermediate and upper ground ends,and it is smaller than that of structures with two different ground elevations.In the plastic state,it is beneficial to improve the torsional effect of the structure by decreasing the size ratio of the part under upper embedding end corresponding to the overall structure.Setting up horizontal grounding components,steel support or viscosity damping in the RC FSSFDEs can improve the torsion resistance.Setting up horizontal grounding components provides the best improvement on torsion effects for structures on rock slope.
作者
韩军
徐雯燕
夏纯皇
刘立平
李英民
HAN Jun;XU Wenyan;XIA Chunhuang;LIU Liping;LI Yingmin(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing 400045,China)
出处
《地震工程与工程振动》
CSCD
北大核心
2024年第6期46-58,共13页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金项目(51638002)
重庆市建设科技项目(城科字2021第1-5)。
关键词
掉层RC框架结构
多台地
有限元分析
扭转效应
抗扭设计
RC frame structure supported by foundations with different elevations(FSSFDE)
multiple different elevations:finite element analysis
torsional effect
torsion resistance design
